Method and apparatus for interrupting high tension circuits



Feb. 21, 1933.

s. RUPPEL 1,898,900

METHOD AND APPARATUS FOR INTERRUPTI NG HIGH TENSION CIRCUITS Fig/ FiledSept. 3, 1927 3 Sheets-Sheet l Inventow: S'gwart Ruppel, by if/0A HisAttovneg.

S. RUPPEL Feb. 21, 1933.

METHOD AND APPARATUS FOR INTERRUPTING HIGH TENSION CIRCUITS 3Sheets-Sheet 2 Filed Sept. 3, 1927 l l I 1 Q W .F tun w n t 8 T Q A W sIm w 5 RUPPEL Feb.- 2-1, 1933.

METHOD AND APPARATUS FOR INTERRUPTING HIGH TENSION CIRCUITS Filed Sept.3. 1927 3 Sheets-Sheet 3 niouvniliibm na,issiizsii.ii5 i aiww W 1Patented'Feb. 21, 1933 SIGWAB'J. scrum, or rmxronr-on-mn-usm, ennmimrMETHOD AND APPARATUS FOR INTERRUPTING HIGH TENSION CIRCUITS Applicationfiled September 8, 1927, Serial H0. 217,488,111111 in Germanylay 18,

My invention relates to a method of and apparatus for interrupting hightension-circuits, more particularly to the interruption of a hightension, alternating current power 'are b means of a blastof gas.

It as been proposed to cool the electrodes or contacts of circuitbreakers, betw en" wliich arcing occurs, for the purpose of dissipatingthe large amount of heat generated and for cooling the points of originof the arc. during circuit interruption. Various arran ements heretoforero osed alon this.

line have been unsuccessful due-to the fact that the coolin action didnot take into account the ten ency of the arc to persist.

It has furtlfer been proposed to quench the are by blowing, as byinjecting air. into the gap betweeihthe electrodes, but ,these proposalslikewise have proved unsuccessful 0 in so :tar as high tension electriccircuit breakers for power currents are concerned. A high voltage are,involving correspondingly high velocity of the ions in the arc stream,is far more resistive to the action of 5 a gas or air current than acomparatively weak, low voltage are. This is one of the reasons that thequenching or interruption of high tension power arcs by means ofairunder comparatively low pressure has failed.

In the case of gas or air at low pressure, the

velocity of the gas is not suificient carry the ions and electrons outof the arc path and to tear the are bodily from the are gap. The are,.as above referred to, may be con- 5 sidered a dense and rapidly movingchain of ions formed at the high voltage existing across the circuitbreaker terminals.

A principal object of m invention is the provision of an improve methodof and 9 apparatus for interrupting high tension cirguits by means of a:suitably directed gas last. 1

i I have found that gas or air under high pressure and in a-suitablyconfined and directed current will act on an arc in several ways, oneway being through the velocity attainedpby the gas when expanding underthe influence of pressure. This high at velocity of expanding gasresults in a cooling action during expansion, a cooling action by way ofexchange of gas, that is, the hot gas a surrounding the are beingreplaced by cold gas, and a cooling action by the evaporation of anyliquid present in consequence of a change of pressure during the flow ofthe gas, the aforesaid evaporation of liquid admixed with the gas havingan'action similar to that utilized in refrigerating apparatus.

Thehigh velocity of the gas under pressure will furtherexert a tearingforce on the arc and its points of origin on the electrodes so as tocarry the electrons and ions away from the electrodes and the arc pathitself.

Another way in which the gas acts on the arcs involves the insulating ordielectric properties of the gas. The gas under pressure will also havean insulating efi'ect between the electrodes in view of the fact thatgas under high pressure also ossesses higher dielectric strength andthereibre renders back firing, or reestablishment of arcing through thegas-stream, diflicult or impossible.

The cooling action on the. are of the gas under high pressure is theresult of several effects, one of which is the cooling action on theelectrodes themselves. The electrodes are cooled in difierent places bythe gas stream. If the stren h and the velocity of the gas stream areciently great tomove the are, which tends to stick to a hot point on acorresponding electrode, the arc is drawn out or stretched and thedensity of ions is reduced until the arc is torn by the mechanical forceacting thereon. In other words, the arc stream, including the ionsand.metal evaporated from the electrodes by the heat of the arc, isstretched and diluted by the gas, the' thinner the arc' theless forcebeing requirediortearing or stretchelectrons there formed, the velocityof which is dependent upon the voltage, are torn away by the gas streamprovided the velocity of the gas is sufiicient. The electrons cannotdirectl cross the as stream and will move in a direction de ed by twocomponents; i. e., the velocity of the gas and the velocity of theelectrons. At a corresponding position along this component ofdirection, the size and shape of the electrodes will determine whether asufiicient number of ions can still travel from one electrode to theother so as to sustain the Accordingly, after a certain degreeofseparation ofthe electrodes, the gap between them cannot be bridged byions even if no electrical blocking ofthe gap has been of:

fected by the gas under pressure. The pure ly mechanical elongation ofthe are by the switching operation likewise acts sov as to.

weaken the are by diminishing the density of ions. When the switchstarts its opening movement, the arc is still short and strong andduring this time the gas under pressure will flow through the arc gapwith the greatest power per unit of len th of the arc. The are isthereby elongate and the force of the stream of the compressed gas isnow directed mainly ontothe points of forma tion of the arc.

In accordance with my invention'the gas under pressure is confinedwithin a comparatively narrow space, as for example by causing thegasunder pressure to travel in a sleeve or annular passage or the like sothat sidewise movement of the arc is prevented and the necessaryvelocity of the gas at the polnts of origin of the are within the arcgap is obtained. In a device constructed in accordance with the presentinvention the electrodes may be formedso that one electrode surroundsthe other, the surrounding electrode having a diverging exhaust passageat the restricted portion of which the other electrode coacts.

My invention will be more fully set forth in the following descriptionreferring to the accompanying drawings, and the features of noveltywhich characterize my invention will be pointed out with particularityin the claims annexed to and forming a part of this specification. 7

{Referring tothe drawings, Figs. 1 to 5,

arrows.

inclusive, are diagrammatic illustrations of various electrodearrangements; Fig. 6 is a fragmentary view, partly in section,\ofcircuit breaker electrode structure embodying my invention; 7 is anelevational view, partly in. section, of a gas blast circuit breaker andoperating means therefor; Fig.

8 is a sectional View, taken along the line 88 of Fig. 7; Fig. 9 is aview, partly in section, showing another form of gas blast switch; Fig.10 is a partly diagrammatic illustration of a complete gas blast circuitbreaker and associated operating and controlling means; Fig. 11 is aview, partly in .section, of another form of gas blast circuit breakerusing an additional arc extinguish ing fluid, and Fig. 12 is a view,partly in section, of a' double pole gas blast circuit breaker anditsoperating means.

Referring to Fig. 1 of the drawings, there is shown a surroundingelectrode 1 having a. funnel-shaped or nozzle-like perforation oropening 2 in which the conical shapedelectrode 3 coacts. When theelectrodes 1 and 3 are in engagement the contact. surfaces thereofengage along the inner'wall of the nozzle-like passage 2 so as to closethe same. If now, referring to- Fig. 2, the electrode 3 is moved in thedirection of the are formed between said electrodes and gas under highpressure isdirected across the are gap now formed between the electrodesand through the nozzle-like passage. 2 so as to exhaust in the mannerindicated, the arc will at once he elongated and subjected to thetearing effect of the gas blast. i The gas flow is clearly indicated in2, the gas flowing past the electrode 3 through the annular passage 4and exhausting as at 5 in the general direction of the indicating Thegas which flows through the gap between the electrodes with great forceand velocity acts on the are formed between the points 6 and 7 so as tocarry along with it these points which are the formation or originpoints of the arc. The tendency is, therefore, toprevent reestablishmentof arcingisince the entire contacting surfaces of the electrodes areactively cooled and the arc has little opportunity for sufficientlyheating the electrode metal at any point.

At the same time the density of the ions of the arc stream 8 is greatlydiminished by reason of the elongation of the are which is' alsobroughtabout by the opening of the electrode 3 in the direction indicated,-which is substantially longitudinal of and counter to the gas flow. Theare will be torn and extinguished under all circumstances at the momentwhenthe velocity of the gas has increased far beyond the velocity of theions sothat an ion torn away at one electrode, as .for example electrode3, cannot traverse the gas stream to reach the other ar'cingsurface uponthe electrode 1. The resultant P nally movable into and out ofcontacting encomponent of the ion velocit and gas velocity will bedirected increasingly in the direction of the gas current untll the arcis actually torn and extinguished.

The arrangement illustrated in Fig. 3 involves similar phenomena. Inthis case the gap between the two parts of the electrode 10 is wider andthe points of formation or origin of the are on the electrode 11,therefore, travel from the sides of said electrode towards its tip,tending to unite at a singlepoint. These origin points of the are areparticularly exposed to the blasting action of the gas under pressureexhausting through the opening 10. Accordingly if the tip of theelectrode 11 is covered with insulating material in the form of a layerof gas under pressure, the are simply will be torn off at this point.vAs in the previous instance, the arc stream 8 is stretched andelongated by the gas blast directedthrough the opening 10' and isextinguished in tho same general manner.

, tion, the intermediate surfaces takes place at leaves the a Figs. 4and 5 illustrate another form of electrodes having two points ofinterrupelectrode 12 making contact with an electrode 13 at a point 14,and with 'an electrode 15 at 16. When the electrodes are separated, gasunder pressure is forced across the gaps at 14 and-16 as illustrated inFig. 5, the gas blast acting or! the arcs substantially as describedwith reference to preceding figures.

Fig. 6 illustrates a form of circuit breaker which embodies the abovedescribed principles of operation. -The electrode 17, which in thepresent instance isrod-like in form and may be movable with respect tothe coacting electrode structure 18, is longitudigagement withtheaforesaid electrode structure within a bore 19 formed in an enclosingcasing 20. The enclosing sleeve or casing 20 18 provided with anannular. recess 21 in which the stationary electrode structure 18 isdisposed and a diverging exhaust passage 22 which is'in communicationwith the bore 19 when the aforesaid electrodes are separated. Thestationary electrode structure,

18, which may be ofthe segmental or other suitable type, issubstantially at the restricted portion of the diverging exhaust passage22 so that when gas is directed under high pressure through the bore 19,as indicated by the arrows 23, separation of the electrode the point ofmaxi mum velocity of the gas. Upon downward or opening movement of therod electrode 17,

gas at high pressure is directed, as indicated, through the bore l9, andthe arc gap between the electrodes 17 and 18 to exhaust through thediverging passage 22, it being noted that-the gas approaches the arc gapalong a generally converging ath and trode 24 and terminal 30.

sition. Opening of the switch is gap along a general y divergvmannerpreviously described.

In Figs. 7 and 8 there is shown a gas blast circuit breaker includingrelativelylnovable electrodes 24 and 25 and a rotatable cam 26 foroperating the movable electrode. The stationary electrode 24 is providedwith an exhaust opening 24' in which the contact tip 27 of the movableelectrode 25 coacts. As

.shown, the coacting electrodes engage substantially at the morerestricted portion of the passage 24. For the purpose of increasing thecurrent-carrying capacity of the electrodes, spring contacts 28connected to the stationary electrode 24 are provided so as to engageone end of the electrode 25, and spring contacts 29 electricallyconnected to the stationary terminal 30 are provided so as to makesliding contact with the-other end of the movable electrode. .For thepurpose of supporting the stationary electrode 24 and for providing aconfining passage or gas chainber for gas directed to the varc gap, aninsulating cylinder 31 of suitable material is provided and is disposedbetween the elec- Gas from a suitable source of pressure may be directedinto the gas chamber formed by the insulator 31 by way of apertures 32.

The supporting means for the movable electrode 25 comprises a pin 33secured to the terminal 30, which is in turn supported by the insulators34. The lower part of the electrode 25 comprises an insulating tube 35arranged to be engaged by the operating surfface of the cam 26, the camnormally holding the electrode 25 in the closed circuit po-. eflected bymovement of cam 26 in counter-clockwise direction, as indicated, so thatthe spring 36, which is connected at one end to the electrode 25 and atthe other end to the pin 33,

is effective to retract the electrode 25 causing separation of thecoacting electrode surfaces. At the same time gas under high pressure isdirected through the openings 32 and across the'arc gap formed betweenthe'electrodes to exhaust through the opening 24' and extin guish thearc in the manner previously described. Closing of the switch iseffected by continued rotation of the cam 26 so that the electrode 25 isprojected upwardly to the closed circuit position shown, thereby placingthe spring 36 under tension and in readiness for a subsequent openingoperation.

Referring to Fig. 9, there is illustrated another form of gas blastswitch comprising a hollow insulator 40, an insulating base plate 41 anda supportingring 42. The stationary electrode 43 is mounted at the upperpart of insulator 40 and is provided with a nozzle-like exhaust opening43" communicating with the hollow bore 40 which together with thecommunicating passages 44 define a gas passage leading to the arc gap.The movable electrode 45, which coacts with electrode 43 within theopening 43', isprovided with an'operating stem 46 biasedas desired by aspring 47. Operating means (not shown) are provided to obtain desiredmovement of the electrode 45. The movable electrode is suitablyconnected to an ex-. terior terminal by a conductor 48 mounted in anextension 49 of the insulator 40. Upon downward or opening movementofthe elec trode 45, gas is directed through the openings 44 and 40', toexhaust through the opening 43' across the arc gap formed therein,

thereby extinguishing the arc in the manner previously described.

Fig. 10 discloses a complete gas blast circuit breaker connected inparallel with an oil circuit breaker, for example, and provided with gaspressure supply and control means. It will be understood, of course,that the oil circuit breaker is not an essential part of the arrangementshown. In the present instancethe gas blast circuit breaker 50 isconnected to the oil circuit breaker 51 in such a manner that uponclosing of the device the electrodes 52 and 53 of the gas blast switchare closed subsequent to closing of the contacts 54 and 55 of the oilcircuit breaker, and upon opening the device the gas blast switch hasthe duty of interrupting arcing.

Referring more particularly to the con- ,trol arrangement, movement ofthe control lever 56 to the left causes energization of coil 57and'consequent opening of the valve 58. The .valve 58 controls flow ofgas from the gas tank 59, which contains a suitable supply of gas athigh pressure. Opening of the valve 58 admits gas under pressure to thepipe 60 so as to force upwardly piston 61, closing both, the oil switchand the gas switch.

To this end the piston rod 62, which is directly connected to thecontacts of the oil switch 51, has a lost motion connection with theupper portion of the rod 63 as illustrated. The rod 62 has secured toits upper end a cup-shaped member 64 in which the rod 63 is slidablyguided, the upper inturned edge of the member 64 being arranged toengage a collar 65 forming a part oi the rod 63. he rod 63, which is ofconducting material and comprises. the movable electrode 53,'is insliding conducting engagement with a current collecting ring 66 formingone terminal of the gas switch. The other terminal of the switchcomprises a conducting lug, or the like, connected to the nozzle-likeelectrode 52 so that in the position shown the electrode 52 is mountedat upon separation of circuit is continuous between terminals 66 and 67.When the device is to be opened the control switch 56 is moved to theright, energizing the openingcoil 68 and causing opening of the valve69. Gas-under pressure from the supply tank 59 is admitted by means ofthe pipe 70 to the gas blast switch so as to effect downward movement ofthe piston 61. This causes immediate opening of the contacts 54 and 55of the oil switch and subsequent opening, by reason of the lost motionconnection above described, of the movable rod electrode 53. It will beapparent that this sequence of openingimposes the duty of extinguishingthe are on the gas blast switch, the oil switch serving to carry tion orcasing 71 at the opposite ends of which hollow insulating members orshells 72 and 73 are disposed. The nozzle-like the upper part of theinsulator 72 and the lower part of the insulator 73 is suitably closed,as by the current collecting ring 66, so as to form a gas chamber incommunication with the exhaust opening 52' metallicjgas supply pipe 70includes two branches, one branch 74 arranged to direct gas to the upperside of the piston 61 and the other branch 75, which is directlyconofthe electrode 52. The

nected to the intermediate metallic section 71, arranged to direct gasfor the arc extin guishing blast into the chamber formed by the switchcasing of switch 50. The lower end of the switch casing comprises aninsulating shell 76 housing the aforesaid lost motion connection andmounted on a conduit section 77 which communicates with the pipe 60. V

Since the gas under pressure is directed to the piston 61 and gaschamber of the switch 50 at thesame time, it will be ap-' parent thatgas under pressure is immediately available to extinguish the are termedthe electrodes 52and 53. As the rod electrode 53 is withdrawn into theswitch casing, the gas under pressure traverses at high .velocity theannular arc gap at the restricted portion of the opening 52' so as toblast theare through the comparatively short and diverging passage andextinguish the same.

If desired, a pressure'responsive piston 7 8 normally biased, asby aspring 79, against the gas pressure in the tank 59 may be arranged so asto interruptthe circuit of the control switch 56, therebypreventing-operation of the gas sure in the supply tank is too low. Tothis blast switch when the pres-- trol circuit 81 -may be arranged tocause the pipe 92, the electrodes are at once sepopening of a valveleading to another gas supply container It will be apparent that thepiston 61 may be directly connected to the movable electrode 53 so as tocause operation of the gas blast switch independently of the oil switch51. The control switch 56 permits selective control of the closing andopening valves, subject, of course, to the gas supply pressureresponsive device when such is used.

Fig. 11 illustrates a gas blast switch pro-' vided with means forintroducing another are extinguishing fluid into the arc during the gasblast. To this end a substance 90, which may be either vaporizable orexplosive in character, is, by way of example, directed or'disposedinthe path of the gas blast so as to be picked upby the gas and carriedwith it through the arc gap. The are extinguishing fluid 90 may comprisewater, oil, liquid air or another refrigerating medium, or a substancewhich serves to aid the interrupting action of the gas blast.

The gas blast is directed into the switch casing 91 through a pipe 92which is provided at its entrance to the switch with acup 93 whichcontains the arc extinguishingv fluid 90. The pipe 92 terminates in anup turned nozzle 94 directed towards the arc gap and a branch passage 95for admitting gas to the operating piston 96 to which is connected themovable electrode 97. A stationary electrode 98 having a gas exhaustpassa 98" forms one terminal of the swit the electrode 97 being suitablycon.-

ing downward movement of the piston 105 which is suitably connected tothe bridging member 103 carrying the movable electrodes 106 and 107. Thecircuit is completed through the switch by way of the terminal conductor108, stationary electrode 109, movable electrode 106, conductor ring110, bridging conductor 111 (in lieu of aconducting bridging member),conductor ring 112, movable electrode 107, and the stationary electrode113 of the other pole which is connected to the terminal conductor 114.The switch casings 115 and116, which form the gas chambers of theswitches 101 and 102, respectively, are formed of insulating materialand have mounted at the upper ends thereof the stationary nozzle-likeelectrodes 109 and 113, respectively.

Upon opening of the switch, gas is direeted by way of pipe 117 into bothswitch casings through openings 118 concurrently with actuation oftheoperating piston 105. The two arcs series are traversed by the gas blastin the manner previously described. The closing of theswitch may beeifected by admitting gas to the lower side of the piston 105 by way ofthe pipe 119.

It shouldbe understood that my invention is not limited tospecific-details of construction and arrangement thereof hereinillustrated, and that changes and modifications may occur to one skilledin the art without departing from the spirit of my invention.

I claim:

1. A high tension circuit interrupter comprising a pair of electrodes,one of said electrodes having a passage defined by a di- Yvergingexhaust portion, the other electrode arranged to engage the first-namedelectrode within said passage and at the restricted portion thereof, andmeans for di-' 'recting a gas athigh pressurethrough said restrictedportion to traverse the are formed prising relatively movableelectrodes, one of nected to the other terminal as by a g saidelectrodes having a passage defined by ing conducting ring 99. Gas forclosing the switch may be directed to the lower side of the piston 96through the pipe 100.-

.Upon admission of gas under pressure to arated by downwardmovement ofthe piston 96 and a high velocity gas, together with the arcextinguishing fluid 90, either in liquid or vaporized form, traverse thearc gap at high velocity and exhaust through opening 98 to eguisharcing,

Fig. 12 illustra a double pole. gas blast switch, the separate poles.101 and 102 being interconnected by abridging member 103. Opening ofthe switch is efi'ected by admitgas under presur'e to the pipecausconverging, constricted, and diverging portions, the other electrodehaving a contact surface for engagin the coacting electrode contactsurface within said passage, said contact surfaces being substantiallyat the constricted portion of said passage, means forsep'arating saidelectrodes to form a gap within said passage, and means for directing agas 'at high pressure across said gap and through said passage so as toblow said are through said constricted and diverging portions of ,saidpassage to cause interruption diver as assage 'the other electrode'coacti n g vi ith said first-named electrode within-said passage, andmeans for directing a gas at high pressure through said diverg- 5 ingpassage to exhaust, said electrodes having arcing suriaces separableupon opening. of the circuit substantially at the pointof maximum gasvelocity in said passage.

4. A high tensioncircuit interrupter of the gas blast type comprisingapair of electrodes separable to form a passage through which gas athigh pressure is directed toextinguish arcing between said electrodes,and means for directing another are extinguishing substance into thepath of said gas prior to its flow through the arc within said passage.

5. A gas blast circuitinterrupter comprising. an intermediate metalliccasing having hollow insulators at opposite ends thereof forming a gaschamber, relatively movable electrodes disposed at one end of saidchamber and separable to form a gap through which gas from said chambermay exhaust to interrupt an are within said gap, metallic r pipesconnecting said intermediate casing and chamber to .a source of gaspressure, and valve structure controlling the flow of gas from saidsource.

6. A high tension circuit interrupter of the gas blast type comprisingelectrodes, one of which surrounds the other, separable to form'an arcgap through which a gas is directed to extinguish'arcin'g, the shapeofsaid electrodes defining a path upon separation thereof such that sadgas approaches said arc gap by a path of decreasing cross section andleaves said gap by a path of increasing cross section directly to aregion of low pressure.

In testimony whereofI afiix my signature.

' SIGWART RUPPEL.

